• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.979-982
• /
• 2003

In this study, because of change in electromagnetic force, deformation of the free surface motion of a magnetic fluid is changed. Deformation of the free surface motion of a magnetic fluid for the change in electromagnetic force is discussed and carried out theoretically and experimentally on the basis of Rosensweig Ferrohydrodynamic Bernoulli Equation. Objective of this study explicates free surface motion by electromagnetic force and planes to designed controller. To control free surface of magnetic fluid, it embody designed two-dimensional free surface form of magnetic fluid. By using this characteristics, they applied to oscillator for surface control, flow control, boundary layer control. Strength of magnetic field and height of free surface of magnetic fluid measure as a hall-effect sensor. As performing height control of magnetic fluid, the result will be presented possibility of free surface deformation control.

• Design & Manufacturing
• /
• v.11 no.3
• /
• pp.46-50
• /
• 2017

Press processing is one of the best machining methods capable of mass production, satisfying dimensional, shape and quality among the methods of processing a metal plate. Among them, Fine blanking is a method of obtaining a precise cross-section such as machining of the shear surface shape. In this research, Using SCP-1 and SHP-1 materials. The deformation behaviors of the material flow affecting the die height of the shear section in accordance with the position of the V-ring in the Fine blanking were compared and analyzed. Result of interpretation, It was confirmed that the force acts on the position where the material flow direction accurately forms the die roll that the material of SCP-1 is at a position of 1.5 mm and the material of SHP-1 is at 2.0 mm. As a result, it was confirmed that the state of fo1111ing the shear surface by the V-ring was excellent. Using analysis results, In the experiment, the height of the die roll was considered by applying The position of the V-ring was 1.5 mm in SCP-1 and 2.0 mm in SHP-1. As a result of comparing the height of the die rolls, the height values of the die rolls were different from each other, It has been considered that the tendency of the die rolls to coincide with each other. It is considered that the difference of the die roll height is caused by the pressure input of the V-ring. In this study, the deformation behavior of the material(In addition to the position of the V-ring, the flow direction of the material depends on the shape of the V-ring and the Indentation amount) is considered to be an important factor in determining die roll height.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.168-177
• /
• 2020

Many coastal engineering designs utilize empirical formulas containing the Equivalent Deep-water Wave Height (EDWH), which is normally given a priori. However, no studies have explicitly discussed a method for determining the EDWH and the resulting design wave heights (DEWH) under irregular wave conditions. Unfortunately, it has been the case in many design practices that the EDWH is incorrectly estimated by dividing the Shallow-water Wave Height (SWH) at the structural position with its corresponding shoaling coefficient of regular wave. The present study reexamines the relationship between the Shallow-water Wave Height (SWH) at the structural position and its corresponding EDWH. Then, a new procedure is proposed to facilitate the correct estimation of EDWH. In this procedure, the EDWH and DEWH are determined differently according to the wave propagation model used to estimate the SWH. For this, Goda's original method for nonlinear irregular wave deformation is extended to produce values for linear shoaling. Finally, exemplary calculations are performed to assess the possible errors caused by a misuse of the wave height calculation procedure. The relative errors with respect to the correct values could exceed 20%, potentially leading to a significant under-design of coastal or harbor structures in some cases.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2007.09a
• /
• pp.528-541
• /
• 2007

To get the possible for management and maintenance, it was analyzed the deformation characteristics, such as crest of embankment and concrete face slab, and leakage of concrete faced rockfill dams (CFRD). There are trends that embankment deformation depends on intact strength used rockfills rather than dam height, deformation normal to concrete face slab during the first reservoir filling is occurred more than 80% of the total deformation in general, and the magnitude and trend of concrete face slab deformation is similar to post-construction crest settlement. The results showed that the range of post-construction crest settlement suggested by Sherard and Cooke (1987), and Clements (1984) had a good agreement in the cases using rockfill with very high intact strength, but it had a trend which underestimated crest settlement in the cases using rockfill with medium to high intact strength. The maximum leakage rate in general was observed during the first reservoir filling and long-term leakage rate was rapidly increased when the dam height exceeds approximately 120m.

• Earthquakes and Structures
• /
• v.23 no.2
• /
• pp.139-150
• /
• 2022

In most self-center braces, decreasing residual deformation is possible only by increasing pretension force, which results in lower energy dissipation capacity. On the other hand, increasing energy dissipation capacity means higher values of residual deformation. The goal of this research was to find the best design for a self-centering buckling restrained brace (SC-BRB) system by balancing self-centering capability and energy dissipation. Three, six, and nine-story structures were investigated using OpenSees software and the TCL programming language to achieve this goal. For each height, 62 different SC-BRBs were considered using different values for the pretension force of cables, the area of the buckling restrained brace (BRB) core plate, and the yield stress of the core plate. The residual deformation and dissipated energy of all the models were calculated using nonlinear analyses after cyclic loading was applied. The optimum design for each height was determined among all the models and was compared to the structure equipped with the usual BRB. The residual deformation of the framed buildings was significantly reduced, according to the findings. Also the reduction of the energy dissipation was acceptable. The optimum design of SC-BRB in 6-story building has the most reduction percent in residual deformation, it can reduce residual deformation of building 83% while causing only a 57% of reduction in dissipated energy. The greatest reduction in residual deformation versus dissipated energy reduction was for the optimum SC-BRB design of 9-story building, results indicated that it can reduce residual deformation of building 69% while causing only a 42% of reduction in dissipated energy.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.1
• /
• pp.401-408
• /
• 2019

This study numerically examined the maximum wind pressure distribution of a billboard on the roof of a middle-rise building. The deformation caused by the maximum wind pressure was examined. For the numerical analysis, the signboard was assumed to be installed on $(b)20m{\times}(d)10m{\times}(h)$ buildings. The maximum wind pressure was measured using four models with the standard model and different sizes of the signboard. The numerical analysis showed that the horizontal deformation predominantly occurs as the shape of the signboard becomes closer to a rectangle, and high wind pressure and deformation occur at the corners of both ends. As the height of the signboard increases, vertical deformation predominantly occurs, and static pressure forms on the backside. When the height is lower than the width of the signboard, the wind pressure is concentrated on the center of the roof. Therefore, the distribution of the maximum wind pressure is stable, and the effect of the wind pressure is relatively low as the height-to-width ratio approaches 1.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.7 no.2
• /
• pp.135-140
• /
• 1995

The procedure of wave energy dissipation due to breaking has been investigated with trains of the regular wave. To obtain the data for wave breaking and its deformation, experiments have been conducted by utilizing a horizontal step adjoining to a combined slope of 1/20 and 1/10. After breaking the wave height decreases by dissipation but attains a stable value at some distance from the breaking point Experimental results show that the stable wave is considerably affected by the wave period. The study gives the general form of stable wave height A new one-dimensional wave deformation model is proposed. being coupled with an approximated shoaling coefficient before wave breaking and the new energy dissipation term after breaking. It was compared with the experimental data. It predicts well the wave height deformation before and after wave breaking even on the abrupt change of the depth.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.5
• /
• pp.76-83
• /
• 2018

A cabinet-door integrated finite element model was constructed for a built-in side-by-side refrigerator with an ice dispenser, and its deformation was analyzed using the ANSYS finite element software. As loads, the food load needed to fill in the cabinet and doors and the thermal load occurring during normal operation conditions were taken into consideration. The door height difference (DHD) and door flatness difference (DFD) between the two doors of the freezing and refrigerating compartments were derived. The DHD and DFD under the assembled condition without applied loads satisfied the acceptance criteria specified by the refrigerator manufacturer. It appeared that the food load increases the DFD slightly. The thermal load tends to increase the differences because of the thermal deformation, especially the DFD, of the cabinet and doors.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.191-192
• /
• 2006

The deformation under radial pressure of rectangular dies for metal powder compaction has been investigated by FEM. The explored variables have been: aspect ratio of die profile, ratio between diagonal of the profile and die height, insert and ring thickness, radius at die corners, interference, different insert materials, i. e. conventional HSS, HSS from powders, cemented carbide (10% Co). The analyses have ascertained the unwanted appearance of tensile normal stress on brittle materials, also "at rest", and even some dramatic changes of stress patterns as the die height increases with respect to the rectangular profile dimensions. Different materials behave differently, mainly due to difference of thermal expansion coefficients. Profile changes occur when the dies are heated up to the temperature required for warm compaction. The deformation patterns depend on compaction temperature and thermal expansion coefficients.

• Transactions of Materials Processing
• /
• v.20 no.5
• /
• pp.339-343
• /
• 2011

This paper presents methods for analyzing the extent of cylindrical-shaped void closure. In addition, a quantitative relationship between change in void fraction and height reduction ratio of a compressed specimen is proposed. The height reduction ratio, number of deformation steps and billet rotation were chosen as key process parameters influencing the void closing behavior, namely, the changes in void shape and size during hot open die forging of a large ingot. The extent of void closure was analyzed from microscopic observations and estimated from tensile test results. The tensile strengths of specimens with closed voids and those without were compared for various reduction ratios in height. The results confirmed that void closure occurs at reduction ratios greater than 30 %. The void closing behavior could be expressed as a hyperbolic tangent function of reduction ratio in height, number of paths, and billet rotation. The knowledge presented in this paper could be helpful for optimizing deformation paths in open die forging processes.